The Massachusetts man wanted for the murders of his two young children, wife and mother-in-law was captured today after a brief manhunt.
Thomas Mortimer IV, 43, was arrested by authorities in the town of Bernardston, Mass., close to the Vermont border and 90 miles from the scene of the murders, after a father and son recognized the car he was driving and alerted police.
"Thomas Mortimer IV is now in custody and charged with the brutal horrific murders of four members of his family," Middlesex District Attorney Gerry Leone said at a press conference today.
Mortimer left behind two notes on the family kitchen table admitting to the crime, authorities said.
Leone paraphrased the notes, saying that Mortimer wrote, "I did these horrible things. What I have done is extremely selfish and cowardly. I murdered my family."
Police also announced that the cause of death was "blunt trauma and wounds caused by sharp objects."
Leone said that at noon today Mortimer was spotted in Montague, Mass., where his car had apparently broken down. The father directed his son to copy down the car's license plate number while he helped jump-start the car.
Mortimer left the scene and the father called the police, who then confirmed it was the car they had been looking for.
"Shortly after 1 p.m. today, the police observed the defendant's car in traffic," said Leone. "The officer attempted to pull the defendant over, but the defendant tried to flee and the officer stayed with him and was able to apprehend him."
The arrest warrant for Mortimer was issued earlier today, a day after the bodies of Mortimer's two young children, his wife and mother-in-law were found scattered through his colonial-style home in Winchester, Mass.
"Having been in that scene, it was horrific, disturbing and unspeakable," said Leone. "The acts do not appear to be random."
Leone said they were asked to do a well-being check on the Mortimer family after relatives had not been able to contact them since Monday night.
What they found was shocking: the lifeless bodies of Mortimer's 64-year-old mother-in-law Ragna Ellen Stone, his wife, Laura Stone Mortimer, 41, and his two children, Charlotte, 2, and Thomas V, 4.
His wife, son and mother-in-law were found scattered down a hallway in the home and his little girl was found upstairs in a pool of blood.
Authorities believe an argument over the phone late in the day on Monday may have led to the murders.
"At the end of the work day, Thomas and Laura had a disagreement on the phone that became argumentative," said Leone. "Thomas came home and the argument continued.
"This is just another occasion in marital discord that has occurred between the two for quite some time now," he said.
Mortimer is scheduled to be arraigned Friday morning.
Mortimer Described as 'Calm' and 'Very Cool'
Causes of death have not yet been determined, according to authorities.
Mortimer last was heard from on Tuesday morning when he called in sick to the software company where he was hired less than month ago as a senior sales account executive.
"He had called in sick around 7:30 a.m. on Tuesday but I had missed the call, so I called him back at around 9:30 a.m.," Mike Wergenbauer, Mortimer's supervisor at M&R Consultants Corporation, told ABCNews.com.
"He told me he had been up all night throwing up and generally hadn't had any rest," said Wergenbauer. "We haven't heard from him since. We're very worried."
Wergenbauer, who was one of the people who decided to hire Mortimer, described him as being very "polite" and having "great references."
Anil Shah, the president of the company, said that Mortimer was hired about a month ago but took his first two weeks off to arrange child care for his children.
"He made it clear that he was very involved in their growth and had been out of work until now spending time with [his kids]," said Shah.
Shah said that up until the last minute on Monday night, the last day Mortimer was at work, he was making calls to clients and was making "good progress."
Asked if Mortimer ever showed signs of having a bad temper, Shah laughed.
"Temper? Far from it," said Shah. "He was very calm and very cool. That's why we're worried about him."
Neighbors who knew the family are stunned by the grim discovery.
"It's shocking," neighbor Sam Bejikian told ABC News' Boston affiliate WCVB-TV. "I don't know what to say. I just saw them yesterday, you know, like, playing outside. Very happy family. Very shocking."