The 27-year-old man arrested on charges of murdering three people out walking their dogs had been treated at a psychiatric clinic in Maastricht prior to the killings, the public prosecution department in Limburg has confirmed to the Telegraaf.

Thijs H, who is studying for a Master’s degree in industrial ecology at Delft University, was arrested on Wednesday evening after police put out a nationwide alert. He is suspected of killing three people – two people found dead on heathland in Limburg on Tuesday and a woman whose body was found in woods near Scheveningen at the weekend.

The Telegraaf said on Friday that H had reported to Mondriaan clinic in Maastricht seeking help after the second murders were committed. The paper said the photos of H distributed by police on Wednesday evening came from the clinic’s cameras.

A student who knows H told DutchNews.nl that he is a ‘chill guy’ but a bit odd. On Thursday a string of reports painted him as a social and intelligent young man who worked hard but behaved strangely at times.

H lives in The Hague, where he was reportedly living in a student house, but spent a great deal of time in southern Limburg where he was arrested, police said. According to the Telegraaf, his parents lived in Brunsum.

Local media said there was an incident at the clinic where H was being treated on early Wednesday morning, in which several people were wounded. One person was arrested. The public prosecution department has said there was no link to H.