Why did Cullen Mutrie shoot police officers that raided his home for steroid investigation?

Police officials raided Cullen Mutrie’s house for a steroid investigation. This person shot five police officials at his home. As a result, the Greenland Police Chief Michael Maloney was killed; four police officers were wounded. The next morning this cop-killer and a woman were found dead.
It is supposed that Mutrie was applying steroids at the time of the shootout. Jane Young, the New Hampshire Associate Attorney General, claimed that toxicology reports were waiting in order to find out whether metabolites of steroids were in the body of Cullen Mutrie.
Police officers reported that Cullen Mutrie had had a very muscular physique. He worked at Genetix Fitness in Seabrook. He was described as a man that was 6 feet 3 inches tall. He weighed 275 pounds. During a raid which took place in July 2010 police officers found anabolic steroids at his home. The police officer Wayne Young found them in a coffee table. He said that he had observed a plastic bag with several vials. A vial was with powder; others contained liquid. According to the labels, they were steroids.
The New Hampshire State Crime Lab analyzed the vials. It was reported that the vials contained such preparations, as Trenbolone Acetate, Sustanon 250, Boldenone Undecylenate and Nandrolone Decanoate.
The professor of kinesiology John Miller was asked whether a connection between the deadly actions and aggressiveness due to anabolic steroids could present. The specialist confirmed that it was plausible. But according to him, it is impossible to confirm that there was a direct link between usage of anabolic steroids and the crime.
John Miller supposed that steroids which were on the black market were provided from legal pharmaceutical companies. But he has been mistaken because the majority of steroids which are offered for sales on the black market are produced in underground labs. It is even suspected that Cullen Mutrie manufactured steroids.
Since a link between crimes and steroid use is a controversial question, not only police officers but also correspondents investigate the case connected with Cullen Mutrie.