An animal rights activist has admitted conducting an arson campaign against people he believed had links to the vivisection industry.
Donald Andrew Currie, 39, of no fixed address, pleaded guilty at Reading Crown Court to arson charges and to possessing fire bombs.
He was charged over incidents at homes in Berks and Bucks and at a firm in Somerset, between May 2005 and March.
Currie was remanded in custody pending psychiatric and pre-sentencing reports.
The jobless father-of-three was arrested in March after two homemade bombs, consisting of weed killer and sugar, were found by police underneath Roland Brooks' car, which was parked outside his Caversham home.
Mr Brooks' wife Caroline is a sales and marketing director for a courier firm understood to have dealings with clinical trials groups, an earlier hearing was told.
Currie admitted two counts of possessing an explosive substance with intent to endanger life and seriously damage property.
In relation to a bid to set Mr Brooks' car on fire, Currie admitted attempted arson, but denied aggravated arson.
Currie also admitted aggravated arson in relation to another attack in Beaconsfield, Buckinghamshire, in September 2005, where an incendiary device caused a fire on the doorstep of the home of Paul and Joan Blackburn.
He denied a fifth charge of aggravated arson in relation to a fire at a cardboard box firm in Williton, Somerset, in May 2005, which caused £140,000 damage.
Responsibility for all three incidents was claimed by the Animal Liberation Front (ALF) on its website, according to Thames Valley Police.
The force said Currie targeted homes of individuals connected with Huntingdon Life Sciences on behalf of the ALF.
Acting Deputy Chief Constable Alex Marshall said: "The offences in question today were of a very serious nature and demonstrate the lengths a minority of animal rights activists are prepared to go to for their cause.
"The bravery of the victims, who refused to be intimidated by extremists who targeted their homes and families, coupled with the determination and hard work put in by the detectives on this case, has produced an excellent result."
Prosecutor John Price told the court Currie's pleas were acceptable to the Crown, as he had admitted the most serious offences.
Judge Zoe Smith adjourned sentencing until 28 September for psychiatric and pre-sentence reports.